It is known to use ceramic and organic paints to coat at least a portion of the surface of a glass sheet, to form an opague border around the peripheral marginal surface thereof, for the preparation of automotive windshields, sidelites, and backlites. Such a concealment band is generally applied to the inner surface of the glass sheet (the surface of the glass sheet nearest the vehicle occupants). A major difficulty encountered during the preparation of such coated glass sheets, however, is a lack of adhesion between the coating and the glass sheet. Thus, paint applied to the glass sheet tends to flake or peel off over time.
It is known from the prior art to apply an adhesion promoter to the glass surface prior to the application of the coating material. Such adhesion promoters include organic silanes such as .gamma.-aminopropyltriethoxysilane.
Alternatively, it is known to roughen the surface of the glass, to increase the surface area of the glass exposed to a coating material, and thereby increase the mechanical bonding between the coating and the glass sheet. For example, the surface of the glass sheet may be abraded by a grinding operation or may be treated with an etchant such as hydrofluoric acid.
U.S. Pat. No. 4,849,247 to Scanlon et al. discloses applying high energy ions to the surface of an article sufficient to allow improved adhesion between the article and the surface of a substrate. For example, ions of the substrate material may be implanted into the surface of the article, to prepare a layer of the substrate material on the surface of the article. Thereafter, the article may be adhered to the substrate by conventional techniques such as, for example, brazing or welding. The patent does not, however, disclose the use of high energy ion bombardment to prepare a reticular surface on the substrate, to increase the adhesion of an article thereto by simple mechanical bonding.
It would be desirable to prepare a reticular surface on a glass article by a simple process, so that paint and other coatings applied thereto would adhere more tenaciously.